Gas-incandescent



UNITED STATES PATENT OFFICE.

H. HALL,

OF PHILADELPHIA, PENNSYLVANIA.

GAS-INCANDESCENT.

SPECIFICATION forming part of Letters Patent No. 575,262, dated January12, 1897.

Original application filed July 3, 1896, Serial No. 598,002. Divided andthis application filed November 17, 1896. Serial No. 612,497. (Nospecimens.)

T aZZ whom it 71mg concern Be it known that I, ROBERT MosoHELEs, asubject of the German Emperor, residing at Berlin, in the Empire ofGermany, have invented certain new and useful Improvements inGas-Incandescents; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it IO appertains to make and use thesame.

This invention relates to an improvement in manufacture ofgas-incandescents, the object being to provide a novel composition ofmatter out of which to constitute the incan- I 5 descing filament; andit consists, essentially, in the combination of materials, substantiallyas will be hereinafter described and claimed.

In my studies and investigations with relation to the so-calledincandescent light, by

which I refer to the phenomena produced by the characteristic propertyof certain mixtures of oxids to change the rays of heat into rays oflight, I have found that the oxids exhibiting such phenomena may bedivided, pri- 2 5 marily, into two kinds, which, for the purpose ofconvenience, I designate as carriers and as developers. Carriers areoxids of a high melting-point, and mostly stable. Developers are alwaysvariable oxids, according 0 to the degree of the volatility of the oxidsemployed, and the duration of the appearance of the incandescent lightis a longer or a shorter one. The incandescent light is formed by thecontinuous oxidation and reduction in 3 5 the edge of the flame when theoxids of any element having several stages of oxidation, such as chrome,manganese, cerium, indium, or gallium, are brought into the flame. Thisquickly-changing or alternate process produces a conversion of the raysof heat into rays of light. To make practical use of this physicalphenomenonin the form of incandescent light, it is necessary to applythe oxid of one of the enumerated bodies, this being the developer oflight in finest division, in the edge of the flame not emitting light,and wherein it should be held in a stable position. To this end bodiesare employed that are constant in the glowing heat, such as thorium,

5o aluminium, &c., which bodies I call carriers, because they serve ascarriers for the light-developers. Indium and gallium possess thepeculiarity that they maybe e1nployed in both forms.

It is unnecessary here to enter into any 5 5 lengthy or detailedexplanation with reference to the known combinations and developers,such as thorium and cerium oxid, aluminium and chrome oxid, doc. I willtherefore proceed to describe the observations made by me to the effectthat the oxids of gallium and indium are exceedingly appropriate toserve as carriers as well as developers in producing a constantincandescent light of great intensity and long duration.

I have found that, for instance, thorium, aluminium, or zircon oxid withsmall. additions up to about three per cent. or four per cent. ofgallium or indium at one hand, and indium or gallium oxid with smalladmix- 7o tures of about three per cent. to four percent. of chrome,manganese, or any other valuable oxid on the other hand, show inexquisite manner the incandescent light. This exquisite property permitsof the manufacture of 7 5 incandescent-light bodies containing indium orgallium oxid made by theprocess or method of first providing acombustible fabric and then impregnating it with salt solutions of aboutten per cent. to fifteen per cent. incan- 8o descent residue of thementioned combinations in the quoted proportions of quantity, and afterdrying in the ordinary manner for the production of the skeleton ofashes of the oxids, that is, the solution of the substances 8 5enumerated for the purposes of impregnation, must be such that theresidue resulting from the solution will, after burning, be from ten percent. to fifteen per cent. By the application of heat to the impregnatedcombustible o fabric the said fabric is burned out and the skeletonstructure composed of the infusible earthy oxids is left as a residuecapable of readily incandescing when heat is applied.

I submit the following examples of com- 5 pounds for incandescingfilaments containing indium or gallium.

First. Aluminium nitrate, fifty per cent; indium nitrate, 0.12 per cent;zircon nitrate,

0.05 per cent; Water, 49.83.

Second. Thorium nitrate, twenty per cent. gallium nitrate, 0.15 percent; calcium nitrate, 0.05 per cent; water, 7 9.80 per cent.

Third. Indium nitrate, 30 percent. chrome nitrate, .40 per cent. bariumnitrate, 0.05 per cent; Water, 69.55 per cent.

Manganese may be substituted for the chrome, if desired.

WVhile I have described the use of gallium in various combinations withthe salts of refractory earths, I have not claimed the same herein, assuch subjectmatter is described and claimed in my application, SerialNo. 508,002, filed July 3, 1896, of which the present application is adivision.

Having thus described my invention, What ROBERT MOSCHELES.

Vitnesses:

CHARLES H. DAY, HENRY HARPER.

